Based on our pilot investigations, the proposed study of trabecular endothelium of normal and glaucomatous human eyes in a defined tissue culture environment seeks direct information concerning the morphology, pathophysiology, phagocytic activity, contractile protein content, and drug response of the cells. Throughout the investigation, comparable studies will be carried out on control cultures of corneal endothelium, keratocytes, and fibroblasts. For tissue culture, human and monkey eyes will be used as soon as possible after enucleation. The morphology and behavior of the cultured trabecular cells will be studied in the living state by phase-contrast microscopy and time-lapse cinemicrography, and in fixed specimens by light and electron microscopy. The phagocytic activity of the cultured cells will be assessed by their uptake of latex spheres and human erythrocytes introduced into the culture medium; the contractile proteins will be analyzed by electron microscopy, by immunofluorescent techniques, and by a radioimmunoassay, and quantitifaction will be carried out by SDS electrophoresis and by a microassay method. We will use these parameters to determine the response of the cells to adrenergic agents and pilocarpine. Similar experiments will be carried out on the trabecular cells harvested from trabeculectomy specimens made available from glaucoma patients, undergoing elective surgery. To determine whether or not the trabecular endothelium of the eyes obtained at various postmortem intervals is still metabolically active, the degree of ultrastructural preservation of the endothelial cells will be correlated with the viability and growth potential of the cells in vitro, and their behavior will be compared with that of trabecular cells derived from fresh explants. Our overall objective in this project is to investigate systematically the morphology, and activity of the trabecular endothelium, and the manner in which it is able to regulate, facilitate, or obstruct aqueous outflow, with the prospect of ultimately gaining control of these interactions for therapy, or even prophylaxis, of glaucoma.